android logcatd 日志系统添加

1. device mk脚本中添加logcatd默认配置
   device/qcom/sdm845/sdm845.mk

+PRODUCT_PACKAGES += logcatd
----------------------------------------------------------------
PRODUCT_PROPERTY_OVERRIDES
PRODUCT_DEFAULT_PROPERTY_OVERRUDES += \

                  persist.logd.logpersisted=logcatd \

                  persist.logd.logpersisted.size=40 \

                  persist.logd.logpersisted.buffer=main,system,crash

配置使用logcatd服务保存日志，最多保存40+1个文件，同时抓取main,system,crash缓冲区的数据至文件。

2. system/core/logcat/Android.mk中修改eng版本也编译logcatd

-LOCAL_MODULE_TAGS := debug
+LOCAL_MODULE_TAGS := optional

3. system/core/logcat/logcat.cpp日志文件创建时新增log组用户可以读

-    return open(pathname, O_WRONLY | O_APPEND | O_CREAT, S_IRUSR | S_IWUSR);

+   return open(pathname, O_WRONLY | O_APPEND | O_CREAT, S_IRUSR | S_IWUSR | S_IRGRP);

4. system/core/logcat/logcatd.rc

on property:logd.logpersistd.enable=true && property:logd.logpersistd=logcatd
    # all exec/services are called with umask(077), so no gain beyond 0700
    mkdir /data/misc/logd 0777 root shell   --->root shell
    chmod 0777 /data/misc/logd/  --->root shell
    start logcatd

5. system/core/logcat/logcat_main.cpp

+#include <sys/stat.h>

+#include <sys/types.h>

int main(int argc, char** argv, char** envp)  {

+    umask(000);//修改用户组文件默认权限

       android_logcat_context ctx = create_android_logcat();

下面主要考虑user 版本

type xxx_logcat, domain;
type xxx_logcat_exec, exec_type, file_type, vendor_file_type;

init_daemon_domain(xxx_logcat)

not_full_treble(`allow xxx_logcat shell_exec:file rx_file_perms;')
full_treble_only(`allow xxx_logcat vendor_shell_exec:file rx_file_perms;')

原文链接：https://blog.csdn.net/shusuanly/article/details/80577306